1. Field
This invention relates to rotary printing press saddles. Specifically, it provides a system for securing thin flexible printing plates to rotary printing press saddles. The system permits installation and removal of such plates without requiring the removal of the saddle from a saddle press.
2. State of the Art
It is common practice today to use a printing press saddle to secure a thin flexible printing plate to the rotating drum (cylinder) of a rotary printing press. The saddles may take a variety of shapes and forms, but are typically semicylindrical in shape and adapted to be removably secured to the drum. A number of different techniques and devices are available to effectively secure a saddle to the cylinder of a press. U.S. Pat. No. 3,537,395 discloses such a representative method.
A variety of devices or methods are also available to secure a thin flexible printing plate to a saddle. Representative of such devices are those disclosed in U.S. Pat. Nos. 3,537,395 (Prince); 2,937,593 (Ritzerfeld); 2,512,940 (Janke); and 2,137,851 (Nelson, et al.). The aforementioned Ser. No. 130,090, also discloses a device for securing a thin flexible printing plate to a saddle.
The devices and methods of the prior art have certain shortcomings. They generally do not permit rapid and efficient installation and removal of thin flexible printing plates because the saddle must first be removed from the cylinder of the press and/or because their plate-securing mechanisms are difficult to operate. In some cases (e.g., Nelson, et al.), an entire segment of the press drum must be removed. Moreover, many of the devices fail to assure proper alignment of the flexible plate on the saddle so that unnecessary operator time must be expended to effect proper adjustment and alignment. Further, many of the devices cannot accommodate slight dimensional variances between plates. Thus, a plate may be not as tightly secured to the saddle as desired; or it may not fit at all.
The present invention permits the operator rapidly and efficiently to obtain proper plate alignment notwithstanding slight dimensional variances between plates. Installation and removal of the printing plates may also be accomplished simply and reliably with the saddle attached to the press cylinder (drum). Thus, efficiency in operation and economies of time in printing press operations may be obtained by use of this invention.